From 669856714222cc27d6ce08b80ed774e854830673 Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Wed, 9 Sep 2015 20:14:58 -0400 Subject: [PATCH] Fix minor bug in regexp makesearch() function. The list-wrangling here was done wrong, allowing the same state to get put into the list twice. The following loop then would clone it twice. The second clone would wind up with no inarcs, so that there was no observable misbehavior AFAICT, but a useless state in the finished NFA isn't an especially good thing. --- src/backend/regex/regcomp.c | 19 ++++++++++++------- 1 file changed, 12 insertions(+), 7 deletions(-) diff --git a/src/backend/regex/regcomp.c b/src/backend/regex/regcomp.c index 4000846789..cf6b360494 100644 --- a/src/backend/regex/regcomp.c +++ b/src/backend/regex/regcomp.c @@ -560,21 +560,26 @@ makesearch(struct vars * v, * splitting each such state into progress and no-progress states. */ - /* first, make a list of the states */ + /* first, make a list of the states reachable from pre and elsewhere */ slist = NULL; for (a = pre->outs; a != NULL; a = a->outchain) { s = a->to; for (b = s->ins; b != NULL; b = b->inchain) + { if (b->from != pre) break; + } + + /* + * We want to mark states as being in the list already by having non + * NULL tmp fields, but we can't just store the old slist value in tmp + * because that doesn't work for the first such state. Instead, the + * first list entry gets its own address in tmp. + */ if (b != NULL && s->tmp == NULL) { - /* - * Must be split if not already in the list (fixes bugs 505048, - * 230589, 840258, 504785). - */ - s->tmp = slist; + s->tmp = (slist != NULL) ? slist : s; slist = s; } } @@ -593,7 +598,7 @@ makesearch(struct vars * v, freearc(nfa, a); } } - s2 = s->tmp; + s2 = (s->tmp != s) ? s->tmp : NULL; s->tmp = NULL; /* clean up while we're at it */ } } -- 2.40.0